Just finished building a stand up paddle board and I have some foam and gator grip left and want to make a wakesurf board and not sure on shape. I mostly ride on a friends old 5"6" broadcast and it seems ok, we can drop in from the platform, ride with no rope and cross the wake and ride toeside/heelside no problem. I don't want to just copy that board shape and rocker. I am about 165 lbs and mostly will be surfing on my vlx wake, i am not hard core, just like to carve around and have fun a few times a week after a wakeboard set. medium size wake usually, wedge and around 1000 lbs of ballast

Well, one thing is for sure. If you're going to copy a board, I would not copy the Broadcast

For your size, shouldn't be larger than 5', I would say around 4'6" or so. 19" wide, 1.5" thick. I would go with a three fin set-up so that you could always remove the center fin if you so desired. Maybe others can comment on rocker, etc.